Multi-effect evaporation system



Oct. 1, 1968 P. L. GEIRINGER' 3,403,719

MULTI'EFFECT EVAPORATION SYSTEM 2 Sheets-Sheet 1 Filed Feb. 10, 1965 3 P. GEIRINGER 3,403,719

MULTI-EFFECT EVAPORATION SYSTEM Filed Feb. 10, 1965 2 Sheets-Sheet 2 United p States Patent 7 3,403,719 MULTI-EFFECT .EVAP RATION SYSTEM Paul L. Geiringer,'Eastchester, N.Y., assignor to American Hydrotherm Corporation, New York, N.Y. Filed Feb. 10, 1965, SerQNo. 431,582 9 Claims (Cl. 159-26) ABSTRACT on THE DISCLOSURE A multi-effect evaporation system wherein each effect is enclosed in a separate casing having a plurality of fiat surfaces a portion of which is inclined, and the casing contains a lower interior portion for introducing liquid and an upper interior portion for collecting vapor. The liquid inlet and outlets are comprised of a plurality of orifices in the casing, with the casings of adjacent effects being in abutting relationship with each other in a manner such that the orifices are aligned so that liquid can flow from one effect to another. The tubes are enclosed in a separate compartment and are parallel to the inclined portion of the casing. The vapor generated'in the tubes is collected in the second interior portion which is provided with an outlet for effecting passage thereof to the heating compartment of thenext adjacent effect.

This invention relates to the design of a multi-effect distillation system to purify liquids. The water to be purified by the system herein described may be sea water; salt-containing ground water; water or other liquids containing chemicals, or sewage effluent.

The system disclosed is an embodiment of a new design which permits the arrangement of the various stages close to each other, or within a common container and, in this way, permitting the use of preassembled units of sizes not exceeding the possibility of one-piece shipment. Preassembly in the plant permits mass production at lower cost.

This design should provide savings in space and simplification in operation.

Considerable advantages are gained by arranging the units close to each other and to enclose them, not in cylindrical containers, but in square boxes, and to set them under an incline between 30 up to 60 which permits considerable savings in space and better condensate removal.

The invention described herein has the following important advantages:

(1) Reduction of investment by prefa'brication of major parts.

(2) Reduction in installation costs.

(3) Increased heat transfer coefficient.

An object of this invention is to provide a system with lower resistance for the vapor to travel from one stage to the other.

A further object is to have a simple arrangement of the condensate to travel from one stage to the other.

A further object is to arrange a short passage for the traveling of the feed from one stage to the other.

A further object is to have an arrangement which would improve, by its position, the heat transfer coeflicient, facilitating the removal of condensate from the tube surface.

A further object and details of this invention will be apparent from the description given hereinbefore and the accompanying drawings illustrate the embodiment thereof by way of an example.

FIG. 1 shows a triple evaporator, but can be expanded to many more stages, and the triple evaporator design is given only as an illustration. It is also possible to have 3,403,719 Patented Oct. 1, 1968 the same design adapted to have the steam in the tube and the water outside the tubes; FIG. 2 is a sectional view taken along line 2-2 of FIG. 1; and

FIG. 3 is a view of a-portion of the heat exchanger tubes of FIG. '1 containing small rings for condensate removal. e

Referring to FIG. 1, the particular embodiment described and illustrated herein is to be considered illustrative only. The present invention covers such other modifications and similar design as may readily occur to those skilled in the art within the scope of the combined claims.

Three evaporators, 1, 2, and 3, are arranged in series. The steam produced from the liquid in evaporator 1 heats the tubes of evaporator 2 from the outside. The steam produced from the liquid in the tubes of evaporator 2 beats the tubes of evaporator 3 from the outside, and so on. In detail, the feed water enters at nozzle 4 under pressure sufiicient to overcome the pressure prevailing in the evaporator. The steam enters evaporator 1 at nozzle 5 and heats the tubes 6 by entering space 30 around the tubes. The steam produced in these tubes 6 passes through screen 7 acting as a demister, and damper 42 controlled from steam pressure in space 41 enters into space 31 around tubes 8 of evaporator 2, producing steam again in tubes 8 and transferring this steam to space 43 of evaporator 2, sending this steam through the demister screen 9 and damper 44 controlled from steam pressure in 43, into space 32 surrounding tubes 10 of evaporator 3, producing steam in the tubes and in space 11 and sending it through demister 12 and damper 45 and nozzle 13 to the next stage.

The condensate is taken off the different stages in the following way:

The condensate of evaporator 1 is collected in space 14 and is released throughadjusta'ble orifices 15 to space 16 and through adjustable orifices 17 into space 18, and from space 18, released through nozzle 19 to the next stage through a heat exchanger 20 to preheat the feed Water.

The feed water enters through nozzle 4 to space 21 and is released through adjustable orifices 22 into space 23 and moves out from there through adjustable orifices 24 to space 25. Thus, the flow rate through the orifices may be regulated by the use of a movable slide, for example, as schematically indicated as 101 in FIG. 2 which may be moved to partially close the orifices 24.

One blowdown nozzle 26 is provided to take blowdown from the three stages and release it through heat exchanger 27 to the blowdown area, heating the feed Water. Condensate drains 28 are arranged at low points of the tube sheet in order to facilitate removal of condensate. The different pressures prevailing in evaporators 1, 2, and 3 permit the feed water as well as the condensate to move automatically from one space to the other, so that feed water only has to be pumped into space 21 through nozzle 4.

A feed nozzle 33 is available to take excess feed, if available, to the next stage.

In FIGLZ, a sectional view, a side weir 34 is shown at each evaporator, to secure a certain water level and overflow of the water into the side box 35 from where a circulation pump 36, one for each evaporator, returns it through nozzle 37 to the respective spaces 21, 23, 25 of the respective evaporators. Roofs 38, 39, and 40 of the three evaporators are removable so that the tubes can be easily pulled out.

FIG. 3 shows small rings around the tubes, facilitating the condensate removal.

I claim:

1. A multi-effect evaporation system comprising:

a plurality of evaporation effects, each effect comprising:

a casing, said casing having a plurality of flat surfaces with a portion of said surfaces being inclined, a plurality of inclined tubes positioned in said casing, said tubes being substantially parallel to the inclined portion of the casing, an inclined compartment within said casing surrounding said tubes, first inlet means for introducing a heating fluid into said compartment, second inlet means for introducing another fluid to be vaporized into a first interior portion of the casing, the lower end of each of said tubes being in fluid flow communication with said first interior portion, first outlet means for withdrawing the vaporized portion of said other fluid from a second interior portion of said casing, said second interior portion being in fluid flow communication with the upper end of each of said tubes, second outlet means for withdrawing the unvaporized portion of said other fluid from said first portion of the casing, third outlet means for withdrawing cooled heat ing fluid from said compartment,

the casings of adjacent effects being positioned in an abutting relationship with each other, the first outlet means of an effect being in fluid flow communication with the first inlet means of the adjacent effect whereby vaporized other fluid flows from said interior second portion of an effect to the compartment of the adjacent effect as the heating fluid, and the second outlet means of an effect being in fluid flow communication with the second inlet means of the adjacent effect whereby unvaporized other fluid flows from the first interior portion of an effect to the first interior portion of an adjacent effect as said other fluid.

2. The system as defined in claim 1 wherein the casing has a generally rectangular cross-section, the casing comprising a substantially vertical lower portion; an inclined intermediate portion and a substantially vertical upper portion.

3. The system as defined in claim 1 wherein the second inlet means and the second outlet means are orifices in the casing, the orifices of adjacent effects being in alignment with each other to establish the fluid flow communication between the second outlet means of an effect and the second inlet means of an adjacent effect.

4. The system as defined in claim 3 and further comprising a plurality of small rings mounted on said tubes.

5. The system as defined in claim 3 and further comprising: means for passing cooled heating fluid from a lower portion of the compartment of one effect to the lower portion of the compartment of the adjacent effect.

6. A 'multi-effect evaporation system comprising:

a plurality of evaporation effects, each effect comprising:

a casing, said casing containing a generally vertical lower portion, an inclined intermediate portion, and a generally vertical upper portion, the majority of the surfaces of the casing being flat, said casing containing a first plurality of orifices on one surface of the lower portion of the casing for introducing a liquid into a first interior portion of the casing, and a second plurality of orifices on another surface of the lower portion of the casing for withdrawing unvaporized liquid from the first interior portion,

a closed inclined compartment positioned in the intermediate portion of the casing,

a plurality of inclined tubes positioned in said compartment, said tubes being in fluid flow communication with the first interior portion of the casing and with a second interior portion in the upper portion of the casing,

inlet means for introducing vapor into said compartment,

first outlet means for withdrawing condensate from said compartment,

second outlet means for withdrawing'vaporized liquid from the second interior portion of the casing,

the casings of adjacent effects being positioned in abutting relationship with each other so that the second plurality of orifices of an effect are in alignment with the first plurality of orifices of the next adjacent effect and the second outlet means of an effect is in fluid flow communication with the inlet means of an effect.

7. The system as defined in claim 6 and further comprising, another compartment in said casing, said compartment being open on the top and in fluid flow communication with the second interior portion of said casing whereby excess unvaporized liquid may be collected, and means for withdrawing the unvaporized liquid from said another compartment and recycling the unvaporized liquid to the first interior portion of the casing.

8. The system as defined in claim 7 and further comprising a demister positioned in said second interior portion whereby vapor passes through the demister prior to passing to the second outlet means.

9. The system as defined in claim 8 and further comprising, movable slide means over said orifices whereby movement of the slide regulates the flow rate through the orifices.

References Cited UNITED STATES PATENTS 385,202 6/1888 Rice 15926 753,777 3/1904 Witkowicz 159--17 972,572 10/1910 Prache 159-26 1,637,431 8/1927 Vogelbusch 15926 1,837,964 12/1931 How 159 -26 2,241,209 5/1941 Lea 122510 2,734,565 2/1956 Lockman 159-20 2,759,882 8/ 1956 Worthen et al. 202-174 3,192,132 6/1965 Loebel 159-2 3,228,859 1/1966 Frankel et al. 159-2 3,307,614 3/1967 Rosenblad 15913 FOREIGN PATENTS 931,545 2/1948 France.

OTHER REFERENCES Rosenblad, Worthen and Loebel have been cited as examples of the common procedure of providing contiguous evaporating chambers to conserve material, space and heat.

NORMAN YUDKOFF, Primary Examiner. J. SOFER, Assistant Examiner. 

